A control apparatus of this type is proposed, for example, in Patent Document 1 specified below. This control apparatus is configured in such a manner that a charge and discharge schedule is determined on the basis of a prediction on power demand of a house that can receive power from and send power to an in-vehicle battery and according to an evaluation function by which evaluation becomes higher as a CO2 emission and power costs become lower and charging and discharging of a vehicle is instructed according to the schedule thus determined.
It should be noted, however, that the control apparatus of a type configured so as to determine a charge and discharge schedule on the basis of the prediction as above possibly has an inconvenience that the control apparatus fails to maintain a balance between supply and demand when the prediction turns out to be incorrect.    Patent Document 1: JP-A-2008-54439 (i.e., US 2009/192655)